SOLUTION: Please help me solve this equation by determining which points are solutions to the given system. Y= -1/2x subtract 5 Y= 3/4x subtract 10 Points: (4, -7), (0, -10), (3, -9/2)

Algebra ->  Linear-equations -> SOLUTION: Please help me solve this equation by determining which points are solutions to the given system. Y= -1/2x subtract 5 Y= 3/4x subtract 10 Points: (4, -7), (0, -10), (3, -9/2)      Log On


   

Question 916395: Please help me solve this equation by determining which points are solutions to the given system.
Y= -1/2x subtract 5
Y= 3/4x subtract 10
Points: (4, -7), (0, -10), (3, -9/2)
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!

given:
Y=+-%281%2F2%29x+-+5......eq.1
Y=+%283%2F4%29x+-10......eq.2
Points (x,y): (4, -7), (0, -10), (3, -9/2)
to determine which points are solutions to the given system, solve the system

Y=+-%281%2F2%29x+-+5......eq.1
Y=+%283%2F4%29x+-10......eq.2.. ..substitute y in eq.1
___________________________

%283%2F4%29x+-10=+-%281%2F2%29x+-+5 ......eq.1............solve for x
%283%2F4%29x+%2B%281%2F2%29x+=+10+-+5
%283%2F4%29x+%2B%282%2F4%29x+=+10+-+5
%285%2F4%29x++=+5
5x++=+5%2A4
x=20%2F5
highlight%28x=4%29.....plug in eq. 1 or 2 and find y
Y=+-%281%2F2%29%2A4+-+5 ......eq.1
Y=+-%281%2Fcross%282%29%29%2Across%284%292+-+5
Y=+-%281%2A2%29+-+5
Y=+-2+-+5
highlight%28Y=+-7%29

so, given point (4, -7), is a solution to the given system